This invention relates to a new lock, particularly to one in which the lock latch can be rotated through an angle and the pins in the cylinder of the lock are adjustable in order to suit the notches in a key.
As shown in FIG. 1, the lock has a conventional lock bolt which can extend into the door jamb, a handle is set on one side of the door and is provided with a thumb knob. When it is desired to lock the door, the thumb knob is pushed in. But this kind of lock can be pried or jimmied open easily using hand tools. Thus, this type of lock provides little security. In order to overcome the disadvantages of the above-mentioned lock dead-bolt locks, as shown in B of FIG. 1, appeared in the market. This type of lock is equipped with a dead bolt 2020 and spring bolt 2010. Dead bolt 2020 is designed to have two stages of displacements, which means that any throw or retraction of bolt 2020 requires two rotations of the key. The keyhole 2030 is located outside and inside the door. Therefore, the lock can be locked or unlocked with a key from either side of the door. Inside the lock, there is a locating plate which is used to stop and fix the dead bolt during every stage of displacement. The better antitheft effect of a dead bolt lock has made it more popular, but there are still possibilities of being pried or jimmied open because the movement of its dead bolt is made only in either left or right direction. Besides, in daily life we have a lot of chances to use lock for security purposes, such as front door, rooms, drawers, cars, etc. As each lock can be unlocked only by a specific key, people always have to carry a lot of keys. In this case, keys become a burden to people and it is also inconvenient for people to have to find the correct key.